It is common practice to use adapters comprising standard male and female electrical connectors joined in a back to back configuration for a number of purposes. For example, these adapters are commonly employed to connect daisy chained instruments to a IEEE 488 General Purpose Interface Bus (GPIB). U.S. Pat. No. 4,398,780 discloses a back to back connector configuration used in a GPIB configuration.
Filter components and circuits have also been used in back to back connector configurations. Representative disclosures of filtered adaptor connector assemblies are shown in U.S. Pat. No. 4,215,326; U.S. Pat. No. 4,126,840 and U S. Pat. No. 5,269,704. These adapters employ discrete or monolithic capacitors positioned between oppositely facing electrical connectors. A ground plate or ground member is usually disposed between the two connectors. U.S. Pat. No. 4,126,840 is an example of a device in which standard fifty position plug and receptacle connectors provide the mating connector interfaces for the adaptor. The capacitors in each of these devices are soldered to the connector terminals.
Other examples of electrical connectors in which capacitive elements are soldered to terminal pins in printed circuit boards are shown in U.S. Pat. No. 4,660,907 and in U.S. Pat. No. 4,726,790. The EMI filter connector block disclosed in U.S. Pat. No. 4,660,907 uses commercially available chip capacitors which have a substantially rectangular forme with electrical terminals disposed along opposing edges. Commercially available surface mount capacitors appear to fit this description.
U.S. Pat. No. 5,141,455 discloses an electrical connector in which discrete capacitors are attached to pins in the electrical connector by conductive adhesive. The use of soldering or conductive adhesives typically results in a relatively complicated and therefore relatively expensive assembly.
There are prior art examples in which filter components, such as discrete capacitors have been mounted in electrical connectors without the use of solder, conductive adhesives or some other bonding agent. U.S. Pat. No. 4,930,200 discloses an electrical filter connector configuration in which individual terminal pins in the electrical connector include compliant pin sections for engaging metallized opening in a printed circuit board to which surface mount filter capacitors are soldered. Ground springs are also clipped onto the printed circuit board.
U.S. Pat. No. 5,152,699 discloses a filter connector in which a support plate and the connector housing hold multilayer ceramic capacitors between pins in the connector and resilient portions of a ground plate.
U.S. Pat. No. 5,352,995 discloses an electrical connector jack containing a low-pass or band pass filter which are engaged by the jack contact springs only when a plug is inserted into the jack.
U.S. Pat. No. 5,344,342 discloses an electrical connector in which capacitors are biased against signal terminals by fingers of a grounding spring.